If you don’t want to have bias edges on the outside of your hourglass blocks, you could use a HST die and make QST as shown in the Fons & Porter video linked in Clue 4. Start with making HST that have an unfinished size at least 1-1/4” bigger than the hourglass block finished size. That probably means going up 1-1/2” unless you have a lot of unusual dies. Make the HST, then, as in the video, nest the seams and draw a line from corner to corner at a right angle to the seam. Then sew 1/4” on each side of that line and cut along the line after sewing. You will likely need to trim down. Although this should work, I haven’t tried it so make sure to test it first.